Safety device for electric switches.



F. C. HARRIS.

SAFETY DEVICE FOR ELECTRIC SWITCHES 0 APPLICATION FILED .I'UNE H, 1914.

Patented Nov. 9, 1915.

'WITNESSES FREDERICK o. HARRIS, 0F DULUTIi: MINNESOTA.

SAFETY DEVICE FOR ELECTRIC SWITQHES.

Specificationof Letters Patent.

Patented Nov. 9, 1915.

Application filed June 11, 1914. Serial No. 844,422.

' and is more particularly adapted for use in connection with electric switches of the type known as the knife switch.

One of the objects of this invention resides in the provision of a safety device for electric switches composed -wholly of nonconducting material, and which may be readily applied to any'switch of well known construction.

A further object of this invention resides in the provision of a safety attachmentcr protector for electric switches provided with means for readily attaching the same to the same support which supports the electric switch.

A still further object of this invention resides in the provision of a safety protector for electric switches formed of nonconducting material and provided with means for preventing the accidental displacement of the handle of the switch. And a still further object of this invention resides in the provision of a safety attachment or protector for electric switches for wholly encompassing the metallic portions ofthe switch mechanism thus obviating all danger of personal contact of the body of the operator with the switch.

Another object of this invention resides in the provision of a, safety device for electric switches which is simple in construction, eflicient and durable in purpose and can be manufactured and sold upon the market at a nominal cost.

These and other objects will more fully appear and the nature of the invention more clearly understood by the construction, combination and arrangement of the parts thereof as described in the following specification, defined in the appended claim and illustrated in the accompanying drawings. in which,

Figure l is a perspective view of the safety device showing the manner of applying the same to an electric switch. Fig. 2

is a vertical longitudinal sectional view showing the switch within the safety device, the switch being shown with thecircuit closed.

I desire to here state that the purpose of this invention is to meet a long felt want and to avoid the serious and ofttimes fatal accidents due to exposed electric switches, the invention consists of a safety protector or casing formed of any'well known nonconducting material, though I preferably form the device of fibrous material, the same being capable of ready application to an electric switch without any alterations in the switch construction, and which may be made ofany size in accordance with'the size of the switch to which the protector-is to be used.

Referring to the drawings, 1 denotes the switch support which may be the wall of a building, table, stand or other support, 2 denotes the base of the electric switch secured in any well known manner to the support 1, 3 the binding posts for receiving the incoming wires l, 5 the pivot post of the binding post 3 in which is pivoted the knife switch 6 provided with the handle 7.

Sdenotes corresponding'binding posts for receiving the outgoing wires 9, the binding posts 8 being provided with the spring con tacts 1.0 for receiving the knife switch 6.

The safety device or protector consists of an open ended box or casing comprising the bottom 11 provided with the slots 12 through which the incoming wires 4 pass to the binding posts 3 of the switch, the sides 13 formed of approximately quadrantic shape, and the curved quadra-circular top 1-1 provided at the upper end with the slots 15 for the passage of the outgoing wires 9 leading from the binding post 8 of the switch, the side edges of the bottom 11 and the top H are provided with a plurality of spaced dovetailed recess 17 for receiving the dove-tailed tongues 18 formed 'upon the edges of the quadrantic sides 13. lVhen the parts of the protector are 111 assembled relation, the same forms a com )lete CEISIIIT exce t1n one end being open as shown at 19, this'open end being provided for readily passing the protector or casing over the switch, the surrounding edges of the opening 19 engaging the support 1 of the switch. and in this man- ,ner the metallic portions of the switch are entirely inclosed.

Formed in the circular top 1&1 is the elongated slot 20 beginning at a point slightly removed from the open end 19 and extending downwardly and terminating at a point remote from'the bottom edge of the casing, the slot being of a widthslightly greater than the'dia-meter of the reduced portion of the handle 7 of the switch, the upper end of the slot 20 being circular and enlarged to pro vide for the passage of the enlarged portion of the handle 7, which handle 7 projects outwardly through the slot 20and is adapted to travel therein during the operation of the handlefor the manipulation of the switch, the lower end of the slot 20 being rounded as at 22 at which point the handle rests when the switch is thrown to openthe circuit.

F or preventing the accidental displace- 'ment of the switch handle 7 when the switch is thrown to open the circuit the inwardly projecting curved lug 23 is provided in one of the side walls of the slot 20 and ma point adjacent the rounded end 22 of the slot 20, this lug 23 beingso positioned as to prevent the handle 7 .from being forced upwardly by any accidental means, but does not prevent the handle from being thrown up Wardly for closing the circuit when desired,

' and to provide for the passage of the reduced portion of the handle 7 by the lug 23, the correspondingly curved recess 2% is formed in the opposite wall of the slot 20,

. thus it will be readily seen that when the handle 7 is resting in the rounded end 22 of the slot 20 that any accidental blow upon the handle 7 will not force the handle. 7 upwardly from the fact that the reduced portion of the handle comes in contact with the lug 23 and is thereby limited from further movement, however, should it be desired to force the handle upwardly for closing the circuit it is only necessary to bend the handle laterally into the recess 24 whereby the handle will readily pass by the lug 23 and continue upwardly through the slot 20 until of the protector casing at the opening 19 will engage the surface of the electric switch support 1, the casing being secured to the support 1 by the l.-shaped clips 25 having one of their arms riveted to the sides 13 as at 26,

p the remaining angular disposed arms of the of the switch mechanism;

- While I have here shown and described the preferred form of my invention, I hereby reserve the right to make such alterations and variations therein from time to time as I may deem expedient and which will neither depart from the spirit of this invention nor conflict with the scope of the claim.

Having thus fully described my invention what I claim as new and desire to secure by Letters Patent of the United States, is

A safety device, in combination with an a electric switch, the handle thereof, and the support for said switch, of an open ended casing formed of nonconducting material for inclosing the metallic parts of an electric switch, comprising a bottom, sides, and a top, said top formed with an elongated slot within which said handle operates and an enlarged opening at the upper end of said slot through which said handle ,is initially passed when applying said casing, said top also formed with a recess in one of thewalls inclosing said slot and adjacent the lower end of said slot, and a lug upon the other wall of said slot opposite said recess and projecting into said slot within the path of said handle to prevent the accidental displacement of said handle when positioned in the lower end of said slot.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

FREDERICK C. HARRIS. WVitnesses: V

H. H. PHELPS, GERTRUDE LARSON.

Copies of this patent may be obtained. for five cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

